Adjustable mast and boom for hoists



Dec. 5, 1961 Filed May 21, 1957 Fuel C. T. FALK ETAL ADJUSTABLE MAST ANDBOOM FOR HOISTS 3 Sheets-Sheet 1 INVENTORs CHARLEST.FALK BY Josapu M.FALK ATTY.

Dec. 5, 1961 c. T. FALK ETAL ADJUSTABLE MAST AND BOOM FOR I-IOISTS 3Sheets-Sheet 2 Filed May 21, 1957 FIG.4

INVENTORS CHA RL EST. F Josapn M. FALK ATTY.

3 Sheets-Sheet 3 C. T. FALK ETAL ADJUSTABLE MAST AND BOOM FOR HOISTSDec. 5, 1961 Fileci May 21, 1957 IMF-I INVENTO CHARLES T. ALK

JOSEPH M. FALK ATTY FIG.5

United States. Patent 3,011,652 ADJUSTABLE MAST AND BOOM FOR HOISTSCharles T. Folk and Joseph M. Falk, both of 1720 Cherry St., JohnsonCounty, Kans. Filed May 21, 1957, Ser. No. 660,683 3 Claims. (Cl. 21267)This invention relates to hoisting apparatus and is particularlyintended for use in changing heavy or weighty tires as used on earthmoving equipment. These tires are very large and heavy and special craneor hoist facilities are necessary for expeditious handling in the field.Tires of the character being considered are normally cartied in anupright position and in servicing the equipment the boom or hoist mustbe high enough to clear the equipment and the hoist must be located fordirect vertical lift with the boom in a horizontal position so that atire can be handled without danger of swing or oscillation.

One of the objects of the present invention is to produce a tireservicing hoist having an extensible mast for over the road underpassclearance which can be extended in the field to clear earth movingequipment with which the hoist is to be used.

Another object is to produce a tire servicing hoist having a boomprovided with sensing means to automatically bring the boom tohorizontal, the mast being rotatable so that the boom can be placed atany desired angular relation thereto.

A further object of the invention is to provide an adjustable supportfor a mast so that the mastcan be plumbed without levelling the truckbody in the field.

With the general objects named in view and others as will hereinafterappear the invention consists in certain new and useful features ofconstruction and organization of parts hereinafter described andclaimed; and in order that it may be fully understood, reference is tobe had to the accompanying drawings, in which:

FIG. 1 is an end elevation of a truck chassis equipped with outriggersfor the support and levelling of the truck in a transverse plane.

FIGURE 2 is a vertical section taken through an extensible, rotatablemast and hoist apparatus embodying the invention.

FIGURE 3 is a fragmental top plan view of the same.

FIGURE 4 is a fragmental end view of the boom and supporting mast.

FIGURE 5 is a diagrammatic view of the control apparatus for the mastand boom.

FIGURE 6 is a side elevation of a mast plumbing support.

FIGURE 7 is a top plan view of the construction shown in FIGURE 6.

FIGURE 8 is a cross section through the drum to illustrate use of a pinto interlock the drum and upper mast section for concurrent rotation.

In the said drawings, where like reference characters identifycorresponding parts in all of the figures, 1 represents a truck chassiswhich is provided with a pair of Outriggers 2 which may be used onuneven terrain to level the truck body and hold same against tippingwhen the hoist is used to lift a heavy load.

Mounted on the truck body is a tubular mast 3 within which a tubularmast extension 4 reciprocates, said mast 4 being gaided at its lower andupper ends by flanges 5 and 6 respectively secured to the masts 4 and 3.Supported on the upper end of the mast 3 and normally rotating aroundthe mast 4 is a drum 7, said drum, however having means hereinafterdescribed so that its rotation can be imparted to the mast 4. Encirclingthe drum 7 is an endless cable 8 which is looped around guide rollersand may be pulled in either direction by manipulation of fluid operatedcylinders 9.

Patented Dec. 5, 1961 For safe highway movement the masts 34 arenormally lowered but when the working site is reached the mast 4 may beextended by operation of a fluid-pressure cylinder 10 centered withinthe masts and having its piston rod connected to a pin 11 carried bymast 4. Upward movement of the mast 4 finally brings a pair of openings12 in alinement with notches 13a in the upper edge of the drum 7 so thata pin 12a or the like, can be passed through the openings 12 and notches13a to interlock mast 4 with the drum so that rotation of the latterwill efiect rotation of mast 4.

Prior to elevation of the mast, if the ground is very uneven, the truckbody may be alined fore-and-aft by blocking up the front or rear wheels.The truck body is then levelled horizontally by manipulation of theoutriggers 2.

However, in most cases the terrain is such that it is only necessary tolevel the boom and this is preferably accomplished by a sensing switchcarried by the boom, as follows: Welded or otherwise secured to theupper end of the mast 4 is a superstructure comprising a pair of sideplates 13 and pivoted on a bolt 14 carried by said plates is a boom 15,shown as of I-beam shape in cross section. This boom may be rocked onthe bolt 14 by extension of the piston rod of a pressure actuatedcylinder 16 carried by the superstructure or side plates 13.

The boom is provided with a rack bar 17 enmeshed with a gear 19 whichmay be rotated by a manually operable endless cable 18, said gear andcable being carried by a chain hoist mechanism 20 so that the hoist maybe moved back and forth along the boom to center it over a load to behandled.

In order to operate the parts as above described reference is to be hadto FIGURE 5 in which 20a is a storage tank for hydraulic fluid, saidtank being connected by a line 21 to a pump 22. The pump 22 dischargesthrough a line 23 to a relief valve 24 into an operating line 25. Ifback-pressure develops in line 25, the relief valve opens to feed thefluid back to the pump through a by-pass line 26. The operating line 25leads through a manually controlled valve 27 to operate the elevatingcylinder 10.

When mast 4 has been fully elevated it is interlocked with the rotatingdrum 7.

The next operation is preferably the levelling of the boom and line 25is connected by a line 28 through a check valve 29 to a manuallycontrolled valve 30 feeding the cylinder 16. Manual valve 30 is openedand fluid pressure will enter cylinder 16 and move the boom. When theboom is horizontal the manual valve 30 may be closed and the boom willremain horizontal as long as valve 30 is tight. However, if the boom isto be automatically held horizontal, valve 30 may be left open and ifthe boom goes above horizontal, a solenoid valve 32 is opened throughthe operation of a sensing switch 31 on the boom to permit excesspressure to bleed ofl and permit the boom to return to horizontalposition.

At this time the mast rotating cylinders 9 may be manipulated to rotatethe mast in the desired direction to center the boom over the work. As asafety means the mast rotating mechanism cannot be actuated until theboom has reached a horizontal position as actuated by the sensing switchon the boom. Connected to the fluid pressure line 21 is a branch line 34leading to a normally closed solenoid valve 35 which is connected to amanually operated four-way valve 36 whereby the cylinders 9 may beconnected selectively to pressurize either of cylinders 9 and exhaustthe other cylinder back through bypass line 37 to the storage tank.

In some cases it may be desirable to plumb the mast independently of thetruck body and in such cases the following mechanism may be used: A baseplate 38 is pivoted along one side on a rod 39 carried by a pair ofupstanding ears 40 resting on the tank bed or other support. Underlyingthe edge of plate 38 opposite that pivoted to rod 31 is a fluid pressureactuated cylinder 41. With this arrangement it will be evident that theplate 38 may be levelled in a plane at right angles to rod'39. The upperedge of plate 38 at right angles to rod 39 carries a rod 42 to which oneedge of a second base plate 43 is pivoted so that said plate 43 may belevelled by a fluid pressure actuated piston 44 resting on the truckbed. By manipulation of cylinders 41 and 44, it will be evident that themast may be readily plumbed regardless of the angle of the truck bed inrelation to the ground plane.

From the above description and drawings, it will be apparent that wehave produced a construction embodying all of the features of advantageset forth as desirable; and while we have described and illustrated thepreferred construction it is to be understood that we reserve the rightto all changes within the spirit and scope of the appended claims.

We claim:

1. In combination, a hydraulic elevating device to be mounted on avehicle, comprising an extensible mast having a fixed and an extensiblesection mounted in a vertical position on the vehicle, the extensiblesection being rotatable within the fixed section, a drum journaled onthe fixed section and detachably keyed to the extensible section, a pairof hydraulically operated pistons mounted on the fixed mast tosimultaneously move in opposite directions, an endless cable encirclingthe drum and operable by the pistons to efiect rotation of the drum, asuperstructure mounted on the extensible mast section, a boom pivoted atone end to the superstructure for movement in a vertical plane, amanually operable valve for selectively hydraulically feeding one of thepair of pistons to rotate the drum in the desired direction, a normallyclosed solenoid valve controlling the hydraulic supply to said manualvalve, and a sensing switch on the boom for opening said normally closedsolenoid valve only when the boom is horizontal.

2. In combination, a hydraulic elevating device to be mounted on avehicle, comprising a fixed mast, an extensible mast carried by thefixed mast and axially rotatable in relation thereto, a drum journaledon the fixed mast and keyed to the extnensible mast to rotate the same,a pair of hydraulically operated pistons to simultaneously move inopposite directions, an endless cable attached to the pistons andencircling the drum to rotate the same, a boom pivoted at one end to theextensible mast and adjustable toward and from a horizontal plane, amanually operable valve to selectively feed to actuate the hydraulicpistons, a normally closed valve controlling the supply of hydraulicfeed to the manual valve, and a sensing switch on the boom for openingthe normally closed solenoid valve only when the boom is in horizontalposition.

3. A hoist mechanism comprising, a support, a mast mounted on thesupport, said mast including a rotatable portion mounted for rotation ona substantially vertical axis of the mast, a boom pivotally mounted onthe rotatable portionof the mast for up and down swing movement relativethereto, said boom extending outwardly from said mast, a power source,power means actuated from said power source and operatively connected tosaid rotative portion of the mast for rotating same for swinging theboom in a circle, power means on the mast and operatively engaged withthe boom and operable by application of power from said power source forefiecting upwardly and downwardly swing movement thereof, a levelresponsive means on the boom, means actuated by said level responsivemeans for shutting ofi the power means to stop rotation of the rotatableportion of the mast when the boom is inclined, and means actuated bysaid level responsive means for controlling application of power to theboom raising and lowering means to swing said boom to substantiallylevel position.

References Cited in the file of this patent UNITED STATES PATENTS

